The epididymis is a tightly coiled tube situated on the back side of each testicle, functioning as the site for sperm maturation, storage, and transport into the vas deferens. Sperm produced in the testis gain the ability to move and fertilize as they travel through the epididymis over several days. An epididymal cyst is a benign, fluid-filled sac that forms within this structure, often resulting from the blockage of small tubules connecting the testicle to the epididymis. This article addresses the relationship between this common condition and male fertility.
Understanding Epididymal Cysts
Epididymal cysts are a common finding, particularly in middle-aged men, though the exact prevalence is difficult to determine since most are asymptomatic. A cyst is considered benign, presenting as a soft, distinct lump separate from the testicle itself. The size varies widely, but many are small and do not cause discomfort.
A distinction is sometimes made between a simple epididymal cyst (clear fluid) and a spermatocele (containing sperm cells). However, the terms are often used interchangeably because they are indistinguishable through physical examination or ultrasound. While many cysts cause no noticeable symptoms, a larger cyst may result in a feeling of heaviness, dull ache, or slight swelling in the scrotum. These symptoms are related to the cyst’s physical presence and size.
Direct Answer: The Relationship to Infertility
In the vast majority of cases, an epididymal cyst does not cause male infertility. These cysts form outside of the testicle and are not involved in hormone production or the initial creation of sperm. The presence of a cyst does not interfere with the overall function of the epididymis or the passage of sperm.
Research supports this conclusion, showing little association between the presence of these cysts and a man’s fertility status. When a cyst is found in a man seeking help for infertility, it is usually an incidental finding, meaning it is present but not the cause of the problem. Other factors, such as issues with sperm production, hormone levels, or blockages in the reproductive tract, are usually responsible for fertility challenges.
When Cysts May Impact Sperm Transport
The rare scenarios where an epididymal cyst could interfere with fertility relate to the mechanics of sperm transport, not sperm production. This interference manifests as an obstructive issue, preventing sperm from traveling from the testicle to the ejaculatory ducts. A large cyst might exert physical pressure on the main channel of the epididymis or the adjacent vas deferens.
If the cyst is large enough to compress these structures, it could lead to obstructive azoospermia, which is the complete absence of sperm in the ejaculate, or oligozoospermia, a severely low sperm count. This direct mechanical blockage is uncommon but represents the most plausible way a cyst itself could impact fertility.
Furthermore, surgical removal of a cyst, known as spermatocoelectomy, carries its own set of risks. The procedure involves dissecting the cyst away from the delicate epididymal tubules. Scarring or damage resulting from this surgery can inadvertently obstruct the passage of sperm. This iatrogenic obstruction is a known complication that can affect the ability of sperm to exit the reproductive tract. For this reason, surgery is reserved for cases where the cyst is causing severe pain or has grown to an extreme size.
Diagnosis and Management
The diagnosis of an epididymal cyst begins with a physical examination of the scrotum by a physician. The doctor can distinguish a cyst, which feels separate from the testicle, from a more serious mass within the testicle itself. To confirm the diagnosis and rule out other possibilities, a scrotal ultrasound is performed.
This imaging technique uses sound waves to visualize the internal structures, confirming that the lump is a fluid-filled sac. For most small, asymptomatic cysts, the recommended management is observation, sometimes called watchful waiting. The cyst is monitored over time, and no immediate treatment is needed.
Intervention is reserved for cysts that are causing significant pain, have grown very large, or are confirmed to be the cause of an obstructive fertility issue. The primary surgical treatment is excision, where the cyst is carefully removed while attempting to preserve the surrounding epididymal tissue. Other, less common options include aspiration and sclerotherapy, though these have a higher chance of the fluid reaccumulating.